does it matter when you refuel?
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Suzuka Master
Joined: Nov 2001
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From: TEXAS
does it matter when you refuel?
i was wondering if there was a good practice or method for refueling
I always refuel when im on E and some people say to refuel when at 1/4 of a tank because its bad for the car to refuel at E.
So what are the true facts??
sidemarker
I always refuel when im on E and some people say to refuel when at 1/4 of a tank because its bad for the car to refuel at E.
So what are the true facts??
sidemarker
I usually refill between E and a 1/4. Kinda goes back to my dad telling me it is not good to let the car reach empty because of all the crap that settles on the bottom of the tank. At this point it's just habit.
Senior Moderator
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From: Swansea, MA
Originally Posted by RaviNJCLs
I usually refill between E and a 1/4. Kinda goes back to my dad telling me it is not good to let the car reach empty because of all the crap that settles on the bottom of the tank. At this point it's just habit.
I usually only put in 12-13 gallons when I fillup. I've only seen the low fuel light come on a couple of times. I've always heard the "crap in the bottom of the tank" deal, so I never let my fuel get to low. I used dry gas every so often to remove any water that might be in there and run a bottle of techron thru every year...
You gotta believe that with the advances in technology that tofays gas filters would catch all the "crap" before it hits the injectors, etc....
Back to Four Doors
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From: San Rafael, CA USA
Originally Posted by GreenMonster
I usually only put in 12-13 gallons when I fillup. I've only seen the low fuel light come on a couple of times. I've always heard the "crap in the bottom of the tank" deal, so I never let my fuel get to low. I used dry gas every so often to remove any water that might be in there and run a bottle of techron thru every year...
You gotta believe that with the advances in technology that tofays gas filters would catch all the "crap" before it hits the injectors, etc....
Team Owner
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From: Hellertown, Pa. USA
Originally Posted by RaviNJCLs
my dad telling me it is not good to let the car reach empty because of all the crap that settles on the bottom of the tank.
The car draws from the bottom of the tank ALL THE TIME regardless of how much fuel is in there.
Think about it….if it took gas from the TOP, you wouldn’t be able to drive very far, would you?
I'm Cool
Joined: Jan 2002
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From: Diamond Bar, CA
Originally Posted by Pure Adrenaline
Fuel pumps use fuel to cool down. Running low on fuel all the time is thus bad for the fuel pump because they could overheat.
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Blown is Best
Joined: Jun 2002
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From: Fresno, CA
Originally Posted by Pure Adrenaline
Fuel pumps use fuel to cool down. Running low on fuel all the time is thus bad for the fuel pump because they could overheat.
That's my understanding also. Running on "E" has the potential of shortening fuel pump life.
Doin' da crack shuffle
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From: Philly and Bowie
Originally Posted by Pure Adrenaline
Fuel pumps use fuel to cool down. Running low on fuel all the time is thus bad for the fuel pump because they could overheat.
I never knew that.
Good info.
I fill up on 1/2 tank. I do it because an empty tank can build up condensation. Condensation = water in your tank. Don't know if this can really happen, but that is my logic.
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Suzuka Master
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From: TEXAS
Originally Posted by knight rider
I fill up on 1/2 tank. I do it because an empty tank can build up condensation. Condensation = water in your tank. Don't know if this can really happen, but that is my logic.
sidemarker
I usually fill it when the light comes on. Unless I pass a station that is cheap & I know I need the gas for a trip or something.
Also I feel that tidit about filling up the tank on e when the light is on being harmfull is nonsense. I have never seen this cause any problems. Nor has there been any proof this is nothing then a myth.
Also I feel that tidit about filling up the tank on e when the light is on being harmfull is nonsense. I have never seen this cause any problems. Nor has there been any proof this is nothing then a myth.
Originally Posted by sidemarker
please elaborate on this condensation theory...
sidemarker
sidemarker
I'm not good at physics major, so I can't give you a detailed explanation of how it exactly happens, but I've been told that condensation in the gas tank happens, especially in nearly empty tanks during winter.
Race Director
Joined: Apr 2001
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From: Long Island, NY
I always seem to fill up either right after the light comes on or right before it does. That's the way its always been. I can never justify filling up with 1/4 tank left especially if i'm only driving close to home.
Adventurist.
Joined: Jan 2004
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From: Orange County, CA
Originally Posted by Pure Adrenaline
The gas tank is a confined space. When you're running low on fuel, the ambient temperature could cause condensation inside, which is water.
I'm not good at physics major, so I can't give you a detailed explanation of how it exactly happens, but I've been told that condensation in the gas tank happens, especially in nearly empty tanks during winter.
I'm not good at physics major, so I can't give you a detailed explanation of how it exactly happens, but I've been told that condensation in the gas tank happens, especially in nearly empty tanks during winter.
I have not seen any data to support that refueling whether empty, 1/2, or 1/4 is harmful to the car.
Team Owner
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From: Hellertown, Pa. USA
The condensation facts are true. Mostly in COLD climates with a near empty tank.
The theory is, with a full tank the problem will be minimized and the water will dilute into the gas for the most part.
But if the tank is near empty, it will cause MORE condensation inside and there will be less fuel for it to dilute into.
This could cause the engine to run rough or even the lines to freeze if it’s cold enough.
That’s why in my area during the winter they tell you to keep the tank above half.
Plus it gives you extra reserves if you get stuck in traffic or totally snowbound so you can run the heater.
The theory is, with a full tank the problem will be minimized and the water will dilute into the gas for the most part.
But if the tank is near empty, it will cause MORE condensation inside and there will be less fuel for it to dilute into.
This could cause the engine to run rough or even the lines to freeze if it’s cold enough.
That’s why in my area during the winter they tell you to keep the tank above half.
Plus it gives you extra reserves if you get stuck in traffic or totally snowbound so you can run the heater.
Instructor
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State proof of data. Cite your source(s) or add a link to these claims. Guesses or personal experiences are not concrete, valid forms of proof. For example, in medical school, if you don't know where a source of data came from, never state it. What you're supposed to say each and every time is, "I don't know, but I will research it and get back to you."
Team Owner
Joined: Oct 2000
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From: Hellertown, Pa. USA
Originally Posted by Roleez
State proof of data. Cite your source(s) or add a link to these claims. Guesses or personal experiences are not concrete, valid forms of proof. For example, in medical school, if you don't know where a source of data came from, never state it. What you're supposed to say each and every time is, "I don't know, but I will research it and get back to you."
This is a car board, not a medical review.
Originally Posted by Roleez
State proof of data. Cite your source(s) or add a link to these claims. Guesses or personal experiences are not concrete, valid forms of proof. For example, in medical school, if you don't know where a source of data came from, never state it. What you're supposed to say each and every time is, "I don't know, but I will research it and get back to you."
I don't think anybody here takes things that seriously. And to be honest, there's quite a few people on here that I don't need proof of data from.
Don't worry about it.
Burning Brakes
Joined: Sep 2004
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From: Los Angeles (San Gabriel)
Originally Posted by Shawn S
The condensation facts are true. Mostly in COLD climates with a near empty tank.
The theory is, with a full tank the problem will be minimized and the water will dilute into the gas for the most part.
But if the tank is near empty, it will cause MORE condensation inside and there will be less fuel for it to dilute into.
This could cause the engine to run rough or even the lines to freeze if it’s cold enough.
That’s why in my area during the winter they tell you to keep the tank above half.
Plus it gives you extra reserves if you get stuck in traffic or totally snowbound so you can run the heater.
The theory is, with a full tank the problem will be minimized and the water will dilute into the gas for the most part.
But if the tank is near empty, it will cause MORE condensation inside and there will be less fuel for it to dilute into.
This could cause the engine to run rough or even the lines to freeze if it’s cold enough.
That’s why in my area during the winter they tell you to keep the tank above half.
Plus it gives you extra reserves if you get stuck in traffic or totally snowbound so you can run the heater.
Not Asian
Joined: Jul 2003
Posts: 13,409
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From: St. Louis
Originally Posted by andyjl
what is considered COLD climates, like is cold considered like the northern states like washington state or where it snows, or is it like southern california where cold is considered 50 degrees?? just curious
Originally Posted by sidemarker
please elaborate on this condensation theory...
sidemarker
sidemarker
If your tank is filled with fuel there is less empty space.
The more empty space (empty tank) the more (wall) area inside of your fuel tank to collect condensation during cold weather.
I don't know if this is applicable in warmer climates but...
OK....lets think logically about this. There is trace amounts of water in your gas tank. Shit happens. And yes, the water comes from outside when the tank is opened and it condenses inside of the tank. Happens a lot when it is humid, but there is always some water vapor in the atmosphere even when it is dry. And, humidity and water vapor content in the air is not always connected to temperature. However, if the tank is properly sealed, there will not be a lot of moisture once it has condensed. When the tank heats back up, unless it gets really hot, the atmosphere inside the empty tank will be essentially gasolene fumes since gasolene is more volatile than water. The amounts of water will therefore not increase unless you open the tank. The relative amount of water will increase because the water does not get used.
Should it affect your engine if you fill up when the tank is really low? Not really. Gas lines do not go to the bottom of the tank, and gas, like oil, floats on water. So unless you are on an incline so that the gas line is at that part of you tank where all the water is, or you have a butt load of water in your tank, it should not be sucked into you gas lines.
Use some dry gas every so often. It contains a fair amount of ethanol in it. It will help the water to mix into the gas and will help it burn off.
Sorry....no citations of information.
Should it affect your engine if you fill up when the tank is really low? Not really. Gas lines do not go to the bottom of the tank, and gas, like oil, floats on water. So unless you are on an incline so that the gas line is at that part of you tank where all the water is, or you have a butt load of water in your tank, it should not be sucked into you gas lines.
Use some dry gas every so often. It contains a fair amount of ethanol in it. It will help the water to mix into the gas and will help it burn off.
Sorry....no citations of information.
Understood, but lets suppose you leave you car (on a 1/4 tank) in the driveway for a period of time. Condensation occurs and you crank that baby up. OK, you burn off the H20 (perhaps) so you still have byproducts of H and O. This will end up as extra stuff in your fuel system and perhaps at the plugs. Kinda convoluted but sounds possible.
Adventurist.
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From: Orange County, CA
Originally Posted by knight rider
Understood, but lets suppose you leave you car (on a 1/4 tank) in the driveway for a period of time. Condensation occurs and you crank that baby up. OK, you burn off the H20 (perhaps) so you still have byproducts of H and O. This will end up as extra stuff in your fuel system and perhaps at the plugs. Kinda convoluted but sounds possible.
Again, only way condensation can occur is if there is a drop in temperature then a rapid increase in temperature, pure physical laws. Now, when does this event occur in a region that has seasonal climate? Next to never.
Frequently we hear it said that the cause of water in fuel tanks is due to condensation. I have long doubted this assertion but the issue has come up so frequently that I was finally motivated to try prove to the point. The basis of my belief or assumption is that:
There isn't enough air volume within a tank to hold much vapor.
On average, tanks are half full, further reducing volume
The amount of water vapor in air is very small, even at 100% humidity
Conditions aren't right to cause condensation in a fuel tank
Research produced the following values for the maximum amount of liquid water in air at the following temperatures:
30C/86F 30 grams/cubic meter
20C/50F 17 grams/cubic meter
10C/13F 9 grams/cubic meter
There are 28 grams per ounce, so 30 grams = 1.07 oz; 17 grams = 0.6428 oz.
A cubic meter equals 264 gallons of liquid volume, therefore:
A 200 gallon tank = 0.76 cubic meter.
At 86F, an empty 200 gallon tank could contain 22.8 grams of water vapor, or 0.81 oz.
At 50F, an empty 200 gallon tank could contain 12.92 grams of water vapor, or 0.46 oz.
Note that this is the maximum amount of water vapor that a completely empty tank could contain, in neither case a full ounce of water.
In order to condense water out of the atmosphere a surface must be much colder than the air. The problem for the condensation in tank theory is; how do we end up with a fuel tank that is much colder than the air? One way would be to have a very cold day that suddenly warms up dramatically, but when does this ever happen? The weather can turn cold very fast, but does not suddenly get very warm.
Aluminum is second only to copper for rapid heat transfer properties; it will therefore adjust to atmospheric temperature changes quickly. Gasoline and diesel fuel, like water absorb [sic] heat and cold slowly. Thus one might expect to see sweating on the outside of a tank as the day warms up from cold mornings, but do we?
This issue first came up a number of years ago over a question of whether internal engine rusting could be due to condensation caused by sudden temperature changes as from day to night and vice versa. Since that time, inspection of hundreds of engines showed that rust only occurs on the underside of valve covers due to water contamination of the oil. Very few engines have rusty undersides of valve covers, thereby proving the point that ice cold engine blocks in the morning don’t sweat at it warms up during the day. If that is true, then how could it be true that fuel tanks sweat?
There isn't enough air volume within a tank to hold much vapor.
On average, tanks are half full, further reducing volume
The amount of water vapor in air is very small, even at 100% humidity
Conditions aren't right to cause condensation in a fuel tank
Research produced the following values for the maximum amount of liquid water in air at the following temperatures:
30C/86F 30 grams/cubic meter
20C/50F 17 grams/cubic meter
10C/13F 9 grams/cubic meter
There are 28 grams per ounce, so 30 grams = 1.07 oz; 17 grams = 0.6428 oz.
A cubic meter equals 264 gallons of liquid volume, therefore:
A 200 gallon tank = 0.76 cubic meter.
At 86F, an empty 200 gallon tank could contain 22.8 grams of water vapor, or 0.81 oz.
At 50F, an empty 200 gallon tank could contain 12.92 grams of water vapor, or 0.46 oz.
Note that this is the maximum amount of water vapor that a completely empty tank could contain, in neither case a full ounce of water.
In order to condense water out of the atmosphere a surface must be much colder than the air. The problem for the condensation in tank theory is; how do we end up with a fuel tank that is much colder than the air? One way would be to have a very cold day that suddenly warms up dramatically, but when does this ever happen? The weather can turn cold very fast, but does not suddenly get very warm.
Aluminum is second only to copper for rapid heat transfer properties; it will therefore adjust to atmospheric temperature changes quickly. Gasoline and diesel fuel, like water absorb [sic] heat and cold slowly. Thus one might expect to see sweating on the outside of a tank as the day warms up from cold mornings, but do we?
This issue first came up a number of years ago over a question of whether internal engine rusting could be due to condensation caused by sudden temperature changes as from day to night and vice versa. Since that time, inspection of hundreds of engines showed that rust only occurs on the underside of valve covers due to water contamination of the oil. Very few engines have rusty undersides of valve covers, thereby proving the point that ice cold engine blocks in the morning don’t sweat at it warms up during the day. If that is true, then how could it be true that fuel tanks sweat?
Originally Posted by knight rider
OK, you burn off the H20 (perhaps) so you still have byproducts of H and O. This will end up as extra stuff in your fuel system and perhaps at the plugs. Kinda convoluted but sounds possible.
The bonds between H and O in water will break best with electricity (ie Electrolysis). And if this does happen....Hydrogen is an explosive gas, hence the Hindenburg, plus it is a really clean burning fuel. Oxygen is required for anything to burn, including gasolene.
Adventurist.
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From: Orange County, CA
Well you can always introduce an organic compound (gas) with water and catalyze it with an acid (pour vinigar in your tank 
), that way you can too break up water. Other than that that you cannot break water's chemical properties simply, H-bonding is there, and it's pretty tough to break apart.
), that way you can too break up water. Other than that that you cannot break water's chemical properties simply, H-bonding is there, and it's pretty tough to break apart.
Meat stick
Joined: Jun 2004
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From: Your mom's basement
Originally Posted by RaviNJCLs
Not possible. When you heat up water it is impossible to break the bond between hydrogen and oxygen. It just becomes a gas. You can keep heating the gas and nothing will happen, but the gas will expand.
The bonds between H and O in water will break best with electricity (ie Electrolysis). And if this does happen....Hydrogen is an explosive gas, hence the Hindenburg, plus it is a really clean burning fuel. Oxygen is required for anything to burn, including gasolene.
The bonds between H and O in water will break best with electricity (ie Electrolysis). And if this does happen....Hydrogen is an explosive gas, hence the Hindenburg, plus it is a really clean burning fuel. Oxygen is required for anything to burn, including gasolene.
Originally Posted by NiteQwill
30C/86F 30 grams/cubic meter
20C/50F 17 grams/cubic meter
10C/13F 9 grams/cubic meter.
20C/50F 17 grams/cubic meter
10C/13F 9 grams/cubic meter.
Adventurist.
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From: Orange County, CA
Originally Posted by RaviNJCLs
FYI...30 grams of water is equivalant to less than 1/10 of a can of soda.
That said, as above, a 200 gallon tank would have 0.81 oz of water vapor: most car tanks, are less than 17 gallons.In regions where weather is fluctuating, gas is added with an additive similar to antifreeze, it prevents water from forming from fuel.
Therefore, the amount of water that forms inside a gas tank is negligible to zero.
Originally Posted by RaviNJCLs
Not possible. When you heat up water it is impossible to break the bond between hydrogen and oxygen. It just becomes a gas. You can keep heating the gas and nothing will happen, but the gas will expand.
The bonds between H and O in water will break best with electricity (ie Electrolysis). And if this does happen....Hydrogen is an explosive gas, hence the Hindenburg, plus it is a really clean burning fuel. Oxygen is required for anything to burn, including gasolene.
The bonds between H and O in water will break best with electricity (ie Electrolysis). And if this does happen....Hydrogen is an explosive gas, hence the Hindenburg, plus it is a really clean burning fuel. Oxygen is required for anything to burn, including gasolene.
So, now I want to ask:
Other than the condensation theory, why else (other than running out of fuel) would you not want to wait to go on 'E' before filling up?
Adventurist.
Joined: Jan 2004
Posts: 6,661
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From: Orange County, CA
Originally Posted by knight rider
Got ya
So, now I want to ask:
Other than the condensation theory, why else (other than running out of fuel) would you not want to wait to go on 'E' before filling up?
So, now I want to ask:
Other than the condensation theory, why else (other than running out of fuel) would you not want to wait to go on 'E' before filling up?
Originally Posted by knight rider
I fill up on 1/2 tank. I do it because an empty tank can build up condensation. Condensation = water in your tank. Don't know if this can really happen, but that is my logic.
Originally Posted by knight rider
Got ya
So, now I want to ask:
Other than the condensation theory, why else (other than running out of fuel) would you not want to wait to go on 'E' before filling up?
So, now I want to ask:
Other than the condensation theory, why else (other than running out of fuel) would you not want to wait to go on 'E' before filling up?
Learn to swim
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From: Reno NV
Originally Posted by Roleez
State proof of data. Cite your source(s) or add a link to these claims. Guesses or personal experiences are not concrete, valid forms of proof. For example, in medical school, if you don't know where a source of data came from, never state it. What you're supposed to say each and every time is, "I don't know, but I will research it and get back to you."
I suppose you want it in MLA too?